Bushnell Xtrawide 4x21 (2 Viewers)

[Binastro]

The Xtrawide 4x21 has the neat trick of including both the Hyades and Pleiades star clusters easily in the same field of view.

There are not many binoculars that can do this.

Regards,
B.

 

[Gijs van Ginkel]

Binastro, post 1,
The Bushnell 4x21 has a giant FOV with 300m/1000m, a rather low eyerelief of 15 mm, and transmission values of around 54-55%, but for a price of 20-50 euros, as we can find them here, it is a useful instrument for star gazing as you show.
Gijs van Ginkel

 

[Binastro]

Hi Gijs,

The field is actually wider than the claimed 300m/1000m.

But the magnification is 3.5x for me and maybe you measured 3.4x.

The problem is the curved field and fixed focus.

But objects near the edge of the field are in focus for me without glasses.

I paid about £15 each for my two examples.
They are new old stock.

The Libra 4x22 also just covers the Pleiades and Hyades in the same field, but it is tight.
Field about 16.3 or 16.5 degrees..
My example does focus, although there was a fixed focus version also.

The VisionKing 5x25 doesn't fit both clusters in the same field, at least my example with 15 degree field.

My Minolta afocal adapter has a very flat field of over 30 degrees but only 1.65x magnification, but is useful in light pollution.
It is too big to make a binocular.
There is a Ricoh afocal adapter that is even bigger.
The Nikon 2x adapters can be made into a binocular.

Regards,
B.

 

[Binastro]

The measured field of the 4x21 XtraWide is 18.5 degrees or using twice tan 9.25 degrees this gives 325m/1000m.

The Libra/Dowling and Rowe 4x22 has a measured field of 290m/1000m.

Regards,
B.